2195铝锂合金的热变形行为

在Gleeble-1500热模拟机上实施热压缩试验,研究2195铝锂合金在变形温度360~500 ℃,应变速率0.1~10 s^-1时的热变形行为,并通过OM和EBSD研究了热变形中微观组织的演变。基于动态材料模型理论及Zener-Holloman参数,构建了2195铝锂合金的应变量为50%时的加工图及本构方程。结果表明,流变应力随变形温度降低或者应变速率的增加而提高,高温软化机制包括动态回复与动态再结晶。利用加工图及显微组织分析确定了试验参数范围内热变形过程的最佳工艺参数为480 ℃/10 s^-1;发现失稳区形变组织和再结晶组织呈层状交替分布,且随着变形温度降低,形变组织层厚度增加;稳定区的微观组织具有明显的动态再结晶特征,形变组织基本消失。

Hot deformation behavior of 2195 aluminum-lithium alloy

Hot deformation behavior of the 2195 aluminum-lithium alloy at temperature range of 360-500 ℃ and strain rate of 0.1-10 s^-1 was studied by means of isothermal compression test on the Gleeble-1500 thermal mechanical simulator. The microstructure evolution of specimens upon hot deformation was characterized by using the optical microscopy (OM) and electron backscattered diffraction (EBSD). Processing map and constitutive equation of the 2195 alloy at strain of 50% were developed based on dynamic material model (DMM) theory and Zener-Holloman parameter. The results show that the flow stress increases with the decrease of deformation temperature or the increase of strain rate. The high temperature softening mechanism includes dynamic recovery and dynamic recrystallization. The best process parameters of hot deformation within the range of test parameters are 480 ℃/10 s^-1 by processing map and microstructure analysis; the deformed structure and recrystallized structure are alternately distributed in layers in the instability zone, and as the temperature decreases, the thickness of the deformed structure layers increases; the microstructure of the stable zone has obvious characteristic of dynamic recrystallization, and the deformed structure practically disappears.